Adaptable safety brake system



March 30, 1954 E.. M. BIRD 26739483 ADAPTABLE SAFETY BRAKE SYSTEM FiledMay 9, 1949 3 Sheets-Sheet l Ernesf M. /'rd By WM March 30, 1954 E. M.BIRD ADAPTABLE SAFETY BRAKE SYSTEM 5 Sheets-Sheet 2 Filed May 9, 1949March 30, 1954 E M B|RD v 2,673,483

ADAPTBLE SAFETY BRAKE SYSTEM Filed May 9, 1949 3 Sheets-Sheet 3 i Q "i.m

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lErne's M Bird Bf @Mm WM ym@ Patented Mar. 30, 1954 UNITED STATES FATENTOFFICE ADAPTABLE SAFETY BRAKE SYSTEM Ernest M. Bird, Scranton, Pa.,assignor to `llremier Saf-Brake Co., Inc., Scranton, Pa., a corporationof Pennsylvania 1 claim. 1

This invention relates to novel and useful improvement-s in brakesystems for vehicles.

An object of this invention is to adapt a safety brake system forvarious types of vehicles and for varying strokes of links cooperatingwith the brake cylinder piston rod.

Another object of this invention is to apply'the brakes of the vehicleby operating the brake cam shafts so as to urge the brake shoes againstthe brake drums in response to a relatively low pressure in theconventional fluid pressure operated brake systems.

Another object of this invention is to apply the brake shoe of a vehiclein response to low pressure occasioned by failure, or occasionedpurposely, within the brake system ofthe vehicle whereby a pair ofconcentrically disposed springs within a cylinder which react on apiston are allowed to operate an improved series of links for ultimatelyactuating the brake cam shaft or other equivalent brake elements in thesystem.

A still further purpose of this invention is to improve the generaloperation of the brake system of a truck or other vehicle whereby one ormore Wheels of the vehicle may be held in place for one reason oranother, as when repairing the vehicle or coupling a tractor to atrailer, the holding action taking place through the operation of amajor spring and a servo spring reacting on a piston, the piston beingdisposed in the cylinder suitably mounted on the vehicle underdiscussion.

And another object of this invention is to release the brakes after theyhave been springapplied by manual means so that the vehicle may be movedunder its own power, relying on the emergency or safety brake system foremergency travel to a stop.

Other objects and features of `novelty will become apparent to thoseskilled in the art, in following the descrip-tion of the preferred formof the invention, illustrated in the accompanying drawings, wherein:

Figure 1 isa plan schematic view of a typical ltractor and trailer,portions of the conventional structure being omitted in order that theirnproved brake system attachment may be readily apparent;

Figure 2 is an elevational detail of construction showing the cylinderandits attachingmembers for the rear axle of a trailer as well asthe'means for manually operating the piston rod to overcome the force ofthe springs shown in Figures 15 and 4;

Figure 3 is primarily a plan View of the device shown in Figure 2, thepiston rod being shown in section;

Figure 4 is a longitudinal sectional view taken on the line 4 4 ofFigure 2 and in the direction of the arrows;

Figure 5 is a transverse sectional view showing the arrangement oflinkages of Figure 4 and taken substantially on the line k5--5 of Figure4 and in the direction of the arrows;

Figure 6 is a plan view of one of the links forming a part of theimproved linkage construction;

Figure '7 is a perspective view of the operator for overcoming the forceofthe spring in releasing the shoes from ,the drums after they have beenoperated by means of the said springs;

Figure 8 is a sectional view taken substantially on the line 8 8 ofFigure l and in enlarged detail to show portions of the system;

Figure 9 is an enlargedelevational view of one of the links forming apart of the linkage construction, the .stop for this particular linkagebeing shown in section;

Figure 10 is a sectional view taken on a line lll-l0 of Figure 9 and inthe direction of the arrows;

Figure 11 is a sectional view of the rear axle `having a bracket mountedthereon for connection with the supports shown in Figure 2;

Figure 12 is a sectional view of a special valve used in connection withthe safety brake system;

Figure 13 is an elevational View of one of the valve members;

Figure '14 is an elevational view of another of the valve members; and

Figure 15 is a longitudinal sectional view of a modification of thecylinder-piston arrangement.

The present invention has adaptation in various environments, but isparticularly useful in connection with trucks, Vand specifically thosewhich include tractors and trailers. 'There have been known, and intheprior art there-are brake systems which operateon the auxiliaryprinciple. They are operative in response to .failures of one sort oranother. The presentinvention, to the bestv of my knowledge,.incorporates various structural improvements over what has been done inthe prior art, and particularly over my prior Patent No, 1,997,807.

Reference is made to Figure 1, wherein `a conventional tractor I isillustrated (portions thereof being omitted) and a conventional trailerI2 is shown partially coupled thereto. The trailer has rear Wheels |4and I6, respectively, and brake drums and brake shoes (not shown). Thedrums and shoes are purely conventional in nature and are in no waymodified by utility of the present device. The brake cam shafts and I 8,respectively, extend from the back plates of the immediate brakeassemblies and are connected for operation by means of the usualoperators 22 and 24 (Figure 8). These operators are, in turn, connectedwith the diaphragm-housings 28 receiving fluid (air or liquid) underpressure through the inlet line 26, Each side of the vehicle has anidentical structure, as clearly evident from an inspection of Figure 1.Further, the diaphragm-piston motors 28 are attached to the axle 30 ofthe trailer |2 by any suitable means found conventional in the art, suchVas a bracket 32.

Mounted on the tractor is a pressure tank 36 having various linesoperatively associated therewith. An air pressure inlet line 38 isattached thereto at one end and is adapted to be secured to a pump notshown. Secured to the line 38 is a `branch 40 which is operativelyassociated with the foot brake pedal operated valve in order to permitfluid (either air or an aqueous or petroleum mixture or solution) to beurged under pressure to the line 42. The line 42 is adapted forconnection with the wheel not shown of the tractor.

Also operatively connected with the line is a conduit 46 whichterminates in a valve housing 48. This line introduces uid underpressure into the housing 48 for operating the brakes of the vehicle bymeans of uid pressure. Accordingly, when the valve is set, as disclosedin Figure 12, the iluid under pressure enters the housing 43 through theconduit 46 and is exhausted through the line 50, since the port 52 ofthe Valve head 54 is aligned with the discharge openings 1n the pipe orline 50. Since this line 50 has a branch 58 therein attaching to thetrailer safety brake, the trailer brake may be operated by amanipulation of the handle 60 of the said valve as shown in Figure 12.

However, when the handle 60 is operated a larger amount, the shank 62 isrotated through the medium of the pin and slot connection generallyindicated at 64 in order to turn the valve head 54 so that the dischargeopening 66 is closed by the head 54. This permits no flow through thehousing 48. Upon rotation of the handle 60 a larger amount, the slot 68is communicated with the opening 66 and also the opening 10 provided inthe bottom I2 of the housing 48. Hence, fluid ows through the line andalso through the line '14 which is in communication with the opening 10.This last-mentioned line is operatively connected with the inlet line 46so that a by-pass arrangement results.

In order to maintain the valve in the proper assembled form, suitablepacking 18 is provided in an internally threaded sleeve 80 which iscarried by the housing 48 and a collar 82 which is externally threadedis disposed in the threaded portion of the sleeve, compressing thepacking and forming an effective seal for the shank 62. A spring 84reacts on the plunger head 54 and also the bottom of the sleeve 80,thereby constantly urging the plunger head against the bottom 12 of thehousing 48. In order to suitably mount the housing 48, an arcuatesurface member 86 is disposed on the housing, whereby the housing may bexed to the steering column 89 of the vehicle.

For operating the rear brake shoes of the trailer I2, a conduit 90 isxed in a suitable manner to the trailer and is attached to the brakeline 42 through the intermediate structure of a flexible hose 94 and arigid length of hose 96 which has a valve 88 disposed therein.Accordingly, in order to remove the trailer from the tractor, it is onlynecessary to close the valve 98 and then unfasten the iiexible length ofhose 94. Also, it is apparent that upon normal operation of the brakesystem, fluid under pressure is urged through the line 42 and,consequently, through the line 80, and ultimately through the line 26for actuation of the servo motor units.

On the other side (preferably) of the trailer I2 there is a line |00which is attached to the said line 50 downstream of the branch 58. Avalve |02 is disposed in the line 50 between the branch 58 and theexible hose portion |04 which attaches the line 50 with the conduit orline |00. The said line |00 is used for the purpose of operating thepiston |06 which is disposed in the cylinder |08 (Figures 4 and l5). Alength of exible hose ||0 extends from the rear end of the line |00 andterminates in a conventional coupling type inlet, generally indicated at|I2, and seen best in Figure 4.

The said cylinder |08 is preferably composed of two complementalsections ||4 and I|6 which are connected together by means of bolts,rivets or the like |20 passing through the flanges ||8 and I |9 of thesections. A gasket |22 is interposed between the sections in order tomaintain the cylinder in the substantially air-tight condition.

A main spring |24, together with a servo spring |26 which is inconcentric relationship therewith, is disposed in the cylinder |00. Asmall lip |28 is fixed at the bottom of the cylinder, serving as a seatand centering device for both of the springs, and a similar small lip|30 is disposed on the under surface of the piston disk |32 forming apart of the said piston generally indicated at |06. The sleeve-typespring guide |3I is fixed to the piston in lieu of the lip |30 in themodiflcaton of Figure 15. A piston rod |34 has a reduced shank |36 atone end with the main plate |32 disposed thereon and operativelyengaging the shoulder at the junction of the shank |36 and the largerpart (diameter) of the piston rod |34. A ber or leather wiper |38 formsanother part of the said piston |06 and is disposed on the main plate|32. A metallic washer |40 is disposed on the said ber or leather member|38 and a metallic de-icer type Wiper |42 is disposed thereon. Mountedon the de-icer member 42 is another Washer |44 which has a pair of nuts|46 thereon holding all of the elements in assembled relationship. Itwill be noted that the end of the shank |36 projects an appreciableamount past the nuts |46 whereby the said end may act as a stop when itengages the outer end of the cylinder. This prevents damage to the endsof the resilient material de-icer or wiper |42.

A number of slots |50 are formed in the skirt of the de-icer, therebyforming resilient lingers which scrape on the inside surface of thecylineevaass 5 der |02. The operation and utility o'f the de-icer is inits obvious 'capacity of keeping the interior of the cylinder in acleanly condition.

Disposed on the piston rod |34 is an externally threaded sleeve |52which passes through a suitable opening in the bottom end of thecylinder HI8 and which is threadedly disposed in a boss Hill. rIhis bossis fixed to thefcylinder so that it is immovable with respect to thesleeve and the piston rod. Since the sleeve |52 is disposed on thepiston rod |34 and lthreaded on the boss, rotation of the sleeve movesthe sleeve outwardly of the cylinder. Means for performing this functionby manual operation is provided. Reference is made to Figure 7 whichshows a handle |53 having bifurcations I 59 and I 6d at one end thereof.Each bifurcation has a slot |62 therein which is disposed on the collarIiali having peripheral notches It therein. These notches are engaged bythe lug Idil which passes between the bifurcations |59 and |60. Sincethe slots t2 have the collar |515 loosely disposed therein, the lug ortongue |58 is selectively disposed in the slots, whereby upon rotativemovement of the handle ld, the sleeve is operated inwardly or outwardlyof the cylinder. A stop |16 is disposed on the outer end of the sleeve|52 for en gagement by the ends of the links |12 and |113, respectively.

These links are pivoted intermediate their ends in the yokes |16 and |18(Figure 5) and the links themselves have bifurcations 18d, |22 and |82,|86 at one pair of ends. The opposite pair of ends are apertured as atIBS and Iil, respectively, for pivotal connection with links |92 (Figure8) which have adjustable turnbuckles or couplings at their ends thereof.

Reference to Figure 9 illustrates a linkage connection operativelyassociated with the link |92. There are two of such linkage connectionsprovided as disclosed in Figure l. Each consists of a pitman Istconnected at one end with the link |92 and connected adjacent the otherend with an arm |96 through the medium of a pivot pin |98.

A stop 253|) which is in the form of a flange fixed to the pitman |94 isprovided for connection with an edge surface of the arm |96. lThisallows limited pivotal movement between the arm |86 and the pitman |98whereby movement may be transmitted from the links |12 and |1l,respectively', in one direction. Movement in the other direction willsimply result in mutual pivotal movement between the pitman |94 and thearm |93.

The lower end of the arm |96 is operatively connected with the brake camshafts 2B for operation thereof and, in order to operate the same camshafts 22 by means of the huid pressure system, the operator 22 isattached to the arm Ili' intermediate the ends thereof (Figure 8).Fixing the said links |12 and |14, respectively, for pivotal movement isa pair of brackets 292 and 2li/i, seen in Fig. A6. Each bracket 2M and204i, respectively, is of identical construction. There is a stop orshoulder 206 formed intermediate its ends and at one end there is ayoke. A reduced portion 23S is provided at the opposite end having twoopenings therein. Pins 2M and 2 I1 are passed through these openings.The pin 2li! is further passed through a pair of arcuate slots 2I2 inspaced ears EIS, while the pin 2|'.l which passes through the otheropening is disposed in openings 2li) in the ears or brackets ZIE.Through this structural expedient, the brackets or arms 2|i2 and 2M,respectively, are

mounted for adjustment. Serrations 2 I 8 are sup- '6 `.plied adjacent"the "shoulder 206 which "are 'enmeshed with serrations 22u ysupplied atthe outer ends ofthe 'ears 2|(5. Hence, "once the arms 2F32 and 2M areadjusted they are maintained in the fixed adjusted position. Theadjustment is obrespectively. To make the adjustment, the pins 2M and2|1 are removed from the ears 216 and the serrations 2|8 of the arms areenineshed in the desired position with the serrations 22H of the forwardedges of the ears 2I5, after which the pins 2 I i and 2I'1 arere-inserted.

In operation, the piston |06 is maintained in the position opposite thatshown in Figure 4 by means of air pressure in the brake system. Thismaintains the springs in the compressed position and urges the stop |10against the bifurcations |80, |82, and |84, |86. Hence, the arms aremaintained normally in the outward position at the bifurcations thereof.A nut 226 and a thrust bearing 228 is carried by the outer end of thepiston rod |34 also forming a seat for the bifurcations. When a failurein the line of the conventional brake system occurs or when it isdesired to apply the brakes in the trailer by another means, the springs|24 and |26 which are under compression are allowed to push the pistonIG inwardly until the end of the reduced shank |36 engages the back endof the cylinder. This carries the thrust bearing 228 with the pistonrod, thereby operating the links |14 and |12 pivotally about the yokes|16 and |18, respectively. This in turn is reflected through the variouslinkages in rotative movement of the brake cam shafts in order to applythe brakes.

In order to release the brakes, it is only neces sary to operate thehandle |58 to pull the piston inwardly of the cylinder. Thus, the stopI1!! pushes the arms |14 and |12 pivotaily about the yokes |163 and |18.

In order to mount the cylinder |08, a pair of special brackets areprovided. These brackets are in part secured to the rear axle 239(Figure 11) and include angle irons 232 having a cut-out portion 234adapted to fit the contour of the axle 23%. Supports 236 and 238,respectively, are fixed by means of bolts to the anges of the angleirons 232 and are fixed to the exterior surface of the cylinder |03.

It is apparent that variations may be made without departing from thespirit of th-e invention.

Having described the invention, what is claimed as new is:

In a fluid operated vehicle brake system, a safety brake engagingmechanism for engaging the brakes responsive to a loss of fluid in thesystem including a cylinder having front and rear ends, a pistondisposed in said cylinder, spring means abutting the front end of saidcylinder and urging said piston toward the rear end thereof, a pistonrod secured to said piston and extending slidably through the front endof said cylinder, a boss on the front of said cylinder surrounding saidpiston rod, a sleeve threaded through said boss and slidably embracingsaid piston rod, a stop on the front end of said sleeve, a stop on thefront of said piston rod, diametrically opposite ears on said cylinderadjacent the front end thereof, arms fixed to said ears and extendingforwardly therefrom, links pivotally secured at their central portionsto the free ends of said arms, one pair of ends of said links beingbifurcated and received over said piston rod between said stops,cooperating means on said arms and said ears for adjustably securing thefree ends of said arms at varying distances toward and away from saidpiston rod, said cooperating means including a serrated edge on eachear, and an oiset shoulder on each arm engaging the serrated edge 0f anassociated ear, a pair of removable, longitudinally spaced pins on eachear securing an arm thereto, each ear having opposed arcuate slotstherein through which one of said pins extends to permit selectiveseourement of said arms in adjusted positions.

ERNEST M. BIRD.

References Cited in the file of this patent UNITED STATES PATENTS Number

